By virtue of rich and colorful applications, large-screen and high-performance smart terminals attract more and more users to join ranks of mobile broadband (Mobile Broadband, MBB) users, and bring huge profits to operators, but also cause the operators to encounter unprecedented signaling storms. The signaling storms further lead to frequent overloading of a signaling board in a network device. For example, a large quantity of radio connection setup and signaling release generated by fast dormancy (Fast Dormancy) often causes a control plane to be overloaded first while a service plane still runs normally. Therefore, it is necessary to reduce control plane signaling overhead, reduce signaling exchange in a call process to prevent overloading of the control plane in advance, and therefore enhance network access call capabilities and capabilities of coping with signaling storms.
A mobile communications system, such as a code division multiple access (CDMA) system, is responsible for accessing and processing data services such as voice, short message, and multimedia services of terminal users according to a protocol followed by the system, such as Abis, 3GPP2 IOS A1/A7 interface protocol, and the like. Such personal service data is generally processed within a signaling plane and a service plane only. To implement end-to-end service link setup, signaling exchange of interfaces such as Abis, A1, and A7 must be performed to implement setup of an Abis service link between a base transceiver station (BTS) and a base station controller (BSC, Base Station Controller), an A2 service link between the BSC and a mobile switching center (MSC, Mobile Switching Center), an A3 service link between two BSCs, and the like. The signaling exchange required by the setup of the service links causes signaling between internal modules of the BSC to increase exponentially. Especially, formation of the signaling for setup/teardown of the links imposes a signaling impact on an interface board and a signaling processing unit (SPU) of the existing BSC, which causes the interface board and the SPU of the BSC to become a processing bottleneck.
Refer to FIG. 1A, FIG. 1B, FIG. 2A, and FIG. 2B. FIG. 1A and FIG. 1B are schematic flowcharts of signaling exchange for setting up a call leg and releasing a call leg respectively between a BSC and a BTS in the prior art. FIG. 2A and FIG. 2B are schematic flowcharts of signaling exchange for setting up a call leg and releasing a call leg respectively between a source BSC and a target BSC during a soft handoff in the prior art.
Specifically, in a signaling exchange process for setting up a call leg, which is shown in FIG. 1A, when the call leg is set up by exchanging call setup request signaling and call setup acknowledgement signaling (Abis Setup Req/Abis Setup Ack) in Abis interface signaling between the BSC and the BTS, information about logical resources occupied by the call leg currently set up needs to be notified to a peer network element by exchanging link setup signaling between network elements, that is, call connection signaling and call connection acknowledgement signaling (Abis Connect/Abis Connect Ack), and then according to the received information about logical resources, the internal modules of the BSC perform internal signaling exchange (indicated by an arrow without texts in FIG. 1A) to implement resource allocation and setup for service links of the Abis interface.
In a signaling exchange process for releasing a call leg shown in FIG. 1B, when the call leg is released by exchanging call release request signaling and call release acknowledgement signaling (Abis Release Req/Abis Release Ack) in Abis interface signaling between the BSC and the BTS, information about logical resources occupied by the call leg currently released needs to be notified to a peer network element by exchanging link teardown signaling between network elements, that is, call removal signaling and call removal acknowledgement signaling (Abis Remove/Abis Remove Ack), and then according to the received information about logical resources, the internal modules of the BSC perform internal signaling exchange (indicated by an arrow without texts in FIG. 1B) to implement resource release and teardown for the service links of the Abis interface.
In a signaling exchange process for setting up a call leg during a soft handoff, which is shown in FIG. 2A, when a soft handoff leg is set up by exchanging call setup request signaling and call setup acknowledgement signaling, that is, handoff request signaling and handoff request acknowledgement signaling (A7 Handoff Request/A7 Handoff Request Ack) in 3GPP2 IOS A7 interface signaling between the source BSC and the target BSC, service link setup needs to be implemented between the source BSC and the target BSC and between the target BSC and the target BTS by exchanging link setup signaling between network elements, that is, call connection signaling and call connection acknowledgement signaling (A3 Connect/A3 Connect Ack and Abis Connect/Abis Connect Ack). Internal signaling exchange (indicated by an arrow without texts in FIG. 2A) also needs to be performed between internal modules of each BSC to implement resource allocation and setup for service links of the A3 interface and the Abis interface.
In a signaling exchange process for releasing a call leg during a soft handoff, which is shown in FIG. 2B, when a soft handoff leg is released by exchanging call release request signaling and call release acknowledgement signaling, that is, release target signaling and release target acknowledgement signaling (A7 Drop Target/A7 Drop Target Ack) in 3GPP2 IOS A7 interface signaling between the source BSC and the target BSC, service link teardown needs to be implemented between the source BSC and the target BSC and between the target BSC and the target BTS by exchanging link teardown signaling between network elements, that is, call removal signaling and call removal acknowledgement signaling (A3 Remove/A3 Remove Ack and Abis Remove/Abis Remove Ack). Internal signaling exchange (indicated by an arrow without texts in FIG. 2B) also needs to be performed between internal modules of the BSC to implement resource release and teardown for service links of the A3 interface and the Abis interface.
In the prior art, between the BSC and the BTS, not only call setup and call release are implemented by exchanging signaling, but also service links of the Abis interface of the call leg need to be set up and torn down by exchanging signaling; between the source BSC and the target BSC, not only a handoff is implemented by exchanging signaling, but also the 3GPP2 IOS A3 interface link needs to be set up and torn down by exchanging signaling; and furthermore, resource allocation and setup, and therefore resource release and teardown of service links need to be implemented between internal modules of the BSC by exchanging signaling.
Generally, a CDMA call requires more than 10 soft handoffs averagely; in a link setup process during the setup of a call leg, the BSC needs to consume about 50 to 60 pieces of signaling overhead, and when the call leg is released, link teardown also needs to be implemented by exchanging signaling. Consequently, a signaling process is complicated and a signaling plane load increases massively, which reduces call access capabilities.
Therefore, how to simplify the signaling exchange process during the setup/release of a call leg and reduce the control plane load and enhance capabilities of the signaling processing unit to cope with the signaling storm impact brought by smart terminals is one of urgent problems to be solved currently.